Overcoming Neurogenic “Meta-Inflammation” to Promote Recovery After Spinal Cord Injury

The singular goal of most spinal cord injury (SCI) research programs is to repair the injured spinal cord and restore locomotor function. Unfortunately, restoration of walking is a low priority for most SCI individuals 1. In addition to impaired mobility, SCI causes slow and steady pathological changes in organ systems throughout the body. Failure to recognize and treat multi- organ system pathology as a standard of care may explain why survival rates have not improved for SCI patients (relative to able-bodied individuals) over the past 30 years 2. Emerging data indicate that after SCI, the loss of sympathetic tone and the development of aberrant spinal autonomic reflexes that control immune organs (e.g., spleen) and the major organs that control metabolism (e.g., liver, adrenal gland, muscle, adipose tissue and gut) cause immune dysfunction and multi-organ pathology. Thus, mitigating the onset and downstream consequences of post-injury dysautonomia could improve immune and metabolic homeostasis. Since immune and metabolic processes are normally tightly coupled and are essential for life 3,4, it is likely that most, if not all, co-morbidities that affect SCI individuals (e.g., spontaneous infections in lung or skin, impaired wound healing, non-alcoholic fatty liver disease (NAFLD), chronic depression, atherosclerosis, type 2 diabetes, fatigue and anxiety), can be explained by impaired immunometabolism. Experiments in this proposal are designed to study SCI as a disease of the entire body and will test the overall hypothesis that post-injury dysautonomia breaks neuro-immune homeostasis creating a state of “neurogenic meta-inflammation”. This proposal is an integration of currently funded NINDS R01 grants and new ideas. All experiments and concepts will build on my lab's past successes using both “macroscopic” (systems and networks) and “microscopic” (cells to molecules) tools to study the pathophysiological significance of neuro-immune interactions. Just as recent NIH initiatives have emphasized that cures for human brain disease are likely to arise from better understanding of brain networks or circuits, rather than defects in a single brain region, a cure for SCI is unlikely to originate from a focus only on repairing the injured spinal cord.